Abstract: Objective To evaluate the effects of calcium 1.25 mmol/L (PD4) and calcium 1.75 mmol/L (PD2) in dialysate on peritoneum injury and abdominal local microinflammatory state by comparing the changes of carcinoembryonic antigen 125 (CA125), vascular endothelial growth factor (VEGF), endothelial
nitric oxide synthase (eNOS), and interleukin- 6 (IL- 6) in the effluent from maintenance peritoneal dialysis (PD) patients. Method A total of 48 PD patients treated with PD2 for more than 2 months and followed-up regularly in Dalian Central Hospital from Jun. 2013 to Aug. 2013 were randomly divided into PD4 group and PD2 group. The PD4 group started to use PD4 instead of PD2, and the PD2 group maintained the PD2 dialy -sate. We defined the start time as 0 month and the end time as 6th month. We recorded the clinical indices and stored the effluent samples overnight to measure CA125, VEGF, eNOS and IL-6 by ELISA. Results Thirtyfour patients (n=17 in PD4 group; n=17 in PD2 group) finished the study course. The baseline clinical data were comparable between the two groups. After the treatment for 6 months, CA125 in the effluent decreased in PD2 group (41.54±12.27 U/ml vs. 32.84±9.10 U/ml, t=2.760, P=0.014); eNOS increased in both groups (32.25±7.37 U/ml vs. 46.85±10.04 U/ml, t=-5.463, P＜0.001 for PD4 group; 29.83±8.13 U/ml vs. 52.10±9.49 U/ml, t=-9.918, P＜0.001 for PD2 group); IL-6 increased in both groups (74.67±22.67 ng/L vs. 83.16±23.08 ng/L, t=4.871 P＜0.001 for PD4 group; 70.98±21.59 ng/L vs. 80.05±20.82 ng/L, t=6.804 P＜0.001 for PD2 group); CA125 declined in PD4 group and VEGF increased in both groups, but without statistical significance (P＞0.05). The decrease range of CA125 was less in PD4 group than in PD2 group [-0.05 (-1.15. 1.30) U/ml vs. 2.50 (0.03, 4.85) U/ml, Z=-2.242, P=0.045]. The increase range of eNOS was less in PD4 group than in PD2 group [-13.68 (-19.02, -5.95) U/ml vs. -22.37 (-27.76, -15.77) U/ml, Z=2.197, P=0.04]. There were no statistical differences in the increase rate of VEGF and IL-6 between the two groups (P＞0.05). Conclusion For maintenance PD patients, using 1.25mmol/L calcium dialysate for a short time of period may protect peritoneal mesothelial cells and microvascular endothelial cells without significant influences on peritoneal angiogenesis and local abdominal microinflammation.

Key words: Peritoneal dialysis, 1.25mmol/L calcium dialysate, 1.75mmol/L calcium dialysate, CA125, VEGF, eNOS, IL-6